Chicago — Despite a wave of attacks by Iraqi insurgents Wednesday morning that killed at least 45 people, America's top military officer, Adm. Mike Mullen, says he remains confident in Iraqi security forces as the US prepares to end its combat mission there.

Speaking with press after a speech to the Executives’ Club of Chicago, the chairman of the Joint Chiefs of Staff characterized the attacks as “an effort on the part of Al Qaeda in particular in Iraq to reignite the sectarian violence,” but noted that so far, “it hasn’t happened.”

The attacks came less than a week after the last brigade scheduled to leave moved out of the country – bringing the number of US troops in Iraq down to about 50,000 – the lowest number since the 2003 invasion. Those troops will remain in Iraq until December 2011, but the official combat mission ends on Aug. 31.

The date was originally set with assumption that Iraq would have a new government in place by now. The nation's elections were in March. But negotiations for forming a new government remains deadlocked. Admiral Mullen said that the deadlock has little effect on the US withdrawal.

A deadline getting even more criticism lately – including from within the armed forces – is the July 2011 date that has been set to begin withdrawing troops from Afghanistan. Gen. James Conway, commandant of Marine Corps, said Tuesday that the president’s deadline was “probably giving our enemy sustenance.”

Mullen acknowledged Wednesday that it’s possible some insurgents are looking at it from that perspective, but said that “a lot of the enemy is struggling compared to where they were a few months ago…. From what I see, they’re not focused on July 2011 from the standpoint of whether it makes any difference in their lives.”

He emphasized that many coalition forces will remain in Afghanistan beyond that date, and that many of the details are still uncertain.

“It’s not a run for the exits,” he said. “There will be a transition that will begin then. We don’t know how many and we don’t know where…. We base it on conditions on the ground, and it’s too early to know what those conditions will be.”

More than 1 million men and women have served in Iraq and Afghanistan so far, and many have faced challenges including high rates of suicide and homelessness. Right now, Mullen said, the military is generating homeless veterans at a rate that is four times greater than it did with Vietnam.

Said Mullen: “I hope to inspire local leadership to put in place a model which captures the needs of so many who are coming back,” said Mullen.